Riverside, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 32.7 °F (low) to 58.8 °F (high). Annual precipitation averages 10.8 Inches. Riverside is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.3 °F | 31.7 °F | 0.91 in. |
| February | 18.2 °F | 36.6 °F | 0.65 in. |
| March | 26.6 °F | 48.6 °F | 1.02 in. |
| April | 31.7 °F | 57.7 °F | 1.12 in. |
| May | 39.4 °F | 67.2 °F | 1.64 in. |
| June | 45.9 °F | 76.3 °F | 0.9 in. |
| July | 51.5 °F | 86.7 °F | 0.42 in. |
| August | 49.9 °F | 86.1 °F | 0.58 in. |
| September | 42.4 °F | 75.7 °F | 0.93 in. |
| October | 32.7 °F | 60.8 °F | 1.05 in. |
| November | 23.6 °F | 45.1 °F | 0.72 in. |
| December | 15.7 °F | 32.7 °F | 0.87 in. |
| Annual | 32.7 °F | 58.8 °F | 10.81 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |